1. Field of the Invention
The present invention relates to the underframe structure of a vehicle including the portion joining the main body of the vehicle to the front body or the rear body of the same.
2. Related Art Statement
Hitherto, as shown in FIGS. 20 and 21, a vehicle framing structure has been arranged such that front side members 80 are disposed in the lower portion of the front body in the longitudinal direction of the vehicle, the front side members 80 having rear end portions 80A connected to side sills 82.
Further in the lower portion of the rear body there are provided rear floor side members 88 in the longitudinal direction of the vehicle, the floor side members 88 having front end portions 88A connected to the side sills 82.
However, the front body of the vehicle of the type structured as described above suffers from torsional deformation since the vertically directed portions of the rear end portions 80A of the front side members 80 are bent downwards and also the portions in the transverse (width) direction of the same are bent outward.
Likewise the rear body suffers from torsional deformation since the vertically directed portions of the front end portions 88A of the rear floor side members 88 are bent downwards and the portions directed in the transverse direction of the same are bent outwards.
Therefore, the conventional vehicle framing structure suffers from vibrations at the time of high speed driving due to insufficient rigidity which in particular occurs in joint portions 98 between the main body and the front body and in joint portions 100 between the main body and the rear body.
Technologies relating to the structure as described above have been disclosed in Japanese Utility Model Application Laid-Open No. 63-11279 and U.S. Pat. No. 4,440,435.